// 云函数入口文件
const cloud = require('wx-server-sdk')

cloud.init()
const db=cloud.database()
// 云函数入口函数
exports.main = async (event, context) => {
  var num=event.num
  var openid=event.openid
  var page=event.page
    return await db.collection('express').where({
     _openid:openid
    }).skip(page).limit(num).orderBy('time','desc').get()
}